English: This is a prototypical output of a 'en:spirometer'. The vertical axis signifies the en:volume and the horizontal axis signifies en:time. The bottom left corner equals zero lung volume at the start of the spirometer recording session. The first small en:amplitude part of the en:sinusoid depicts repeated resting state involuntary breathing. The amplitude of this small sinusoid corresponds to the 'Tidal Volume'. The large positive amplitude spike represents voluntary inspiration to maximal volume or 'Total Lung Volume'. The large negative amplitude spike represents forced expiration to the lowest possible en:physiological lung volume called 'Residual Volume'. All of the en:lung volumes commonly referred to in the literature are labeled. Vihsadas 21:31, 18 April 2007 (UTC) Vihsadas (talk) 05:52, 7 March 2008 (UTC) Vihsadas 20:10, 14 April 2007 (UTC)